Everyone has heard of a movie projector because they are used in cinemas to play movies for large audiences. It is a large screen, making the moviegoing experience one of the most exciting pastimes for most people. However, most people might wonder how does a movie projector work when watching a movie.
Wondering how things work is one of the most defining traits of humans and also what has propelled our civilization forward. So, to sate your curiosity, We will go over the inner workings of movie projectors as well as the various types of movie projectors used in cinemas today.
How Does a Movie Projector Work
A movie projector is a mechanical device that plays a movie when you go to the cinema. This mechanical device transfers the images from a roll onto a movie screen. The images are projected on the large screen through the lens of the movie projector.
First working phase
The movie projector continuously rotates movie reels on sprocket-style wheels using an electric motor. The supply reel will serve as the movie’s opening and the takeup reel as its closing. The movie can be used again in the same order when the movie is done. However, it will be on a separate reel.
The movie is briefly exposed to the bulb and lens in the center of the movie projector as it travels along this conveyor belt before continuing toward the takeup reel. The instant the movie is viewed on the lens and shown on the viewing screen is when it is exposed to light.
Second working phase
Moving quickly past the lamp and lens is prevented by a shutter. Xenon bulbs are frequently used in movie projector lights because they are extremely bright and have an illumination time of over 2,000 hours.
Then, the movie roll runs through the sound drum to sync the sound with the picture after passing through the lens. To ensure that the sound and picture are in sync, the sound drum is placed 26 frames away from the lens.
The reel needs to move quickly to provide the impression that the movie is moving. A movie is projected at 24 frames per second via movie projectors. A certain speed is required to make still movie frames appear to be moving to the human eye.
This length of a movie could require numerous reels. A “platter” in a movie projector can align the reels by syncing the movie.
Read more: What Kind Of Projectors Do Movie Theaters Use?
Types of Movie Projectors
With the advancement of technology, we have various projectors today. They begin from the very first Cathode Ray Tube projectors to the laser ones available in recent years. The types of projectors are as follows. So, let’s take a look at each of the types and how they work.
Cathode Ray Tube Projector (CRT)
The oldest type of projectors are known as gun projectors, or their official name, Cathode Ray Tube projectors.
The gun projectors work using a light magnifying lens and three high-bright cathode ray tubes. The tubes are arranged like horizontal traffic lights with red, green, and blue colors. The lights are merged on a phosphor-coated surface, which creates an image.
Liquid Crystal Display Projector (LCD)
The Liquid Crystal Display projector has three panels of liquid crystal and glass. The LCD projector is also designed with three regular and two dichroic mirrors.
LCD projectors work by passing white light through the dichroic mirrors and splitting it into three colors, red, green, and blue.
These three lights are reflected into three separate LCD panels and reconverted to create a single clear image projected on the screen.
Digital Light Processing Projector (DLP)
A DLP projector can process an image with up to 35 million colors, which is more advanced than the human eye. DLP projectors are designed with Digital Micromirror Device chips, made of millions of micromirrors. The more micromirrors are in the chips, the more pixels there will be.
The white light is split into red, green, and blue light and is reflected onto the chip’s mirrors. Then, the tiny mirrors blend the colors and pass them through a lens that will project the image on the screen.
Liquid Crystal on Silicon Projector (LCoS)
LCoS projectors are a mix of LCD and DLP projectors and are the latest to be introduced on the market. The difference between DLP and LCoS projectors is that LCoS are designed with silicon instead of mirrors.
LCoS projectors work by splitting a beam of light into red, green, and blue with the dichroic mirrors and passing it through different filters before it reaches a microdevice. After that, the filtered lights are merged through a prism, and the image is projected on the big screen.
LED Projector
LED projectors can also be considered LCD or DLP projectors because they use light-emitting diodes instead of traditional projector lamps to generate light. LED projectors can use LCD or DLP technology to magnify the image projected on the screen.
Laser Projectors
A laser projector uses a type of light-generating technology instead of an image-generating one. As per its name, a laser projector uses a laser as its light source instead of the traditional bulbs. Laser projectors can also use LCD, DLP, or LCoS technology.
Also read: How Do Laser Projectors Work
Conclusion
Well, we have come to the very end of this article. Hopefully, this gives you an answer to your curiosity, and now you know how does a movie projector work when you are watching a movie on it. As you can see, movie projectors range from highly complex devices to simpler home movie projectors.
However, the basic parts of every movie projector are the spooling system, the lamp, the lens, and the audio system. The parts all work together to project a clear moving image on the big screen, allowing you to enjoy various movies.